The present disclosure relates to a light emitting device, light emitting device package, and an illumination system provided with them.
Group III-V nitride semiconductors have been widely used as the core materials of light emitting devices such as Light Emitting Diodes (LED) and Laser Diodes (LD), in physical and chemical characteristics. The group III-V nitride semiconductors consist of semiconductor materials having the composition equation of InxAlyGa1-x-yN (where 0≦x≦1, 0≦y≦1, and 0≦x+y≦1).
The LED is a sort of semiconductor device that changes electricity into infrared rays or light by using the characteristics of compound semiconductors to input/output a signal, or is used as a light source.
The LED or the LD with nitride semiconductor materials is much applied to the light emitting devices for obtaining light. For example, the LED or the LD is applied as the light sources of all sorts of products such as the light emitting portions of the key pads of cellular phones, electronic display boards and lighting devices.